Actually, given that the models are now in good agreement with the surface AND lower troposphere warming trends, the human contribution to warming due to greenhouse gases will be much better quantified.
Sorry. Until you barcode all the CO2 molecules that come out of my car and my mouth, you can't prove I'm doing it. Just because two sets of thermometers agree doesn't put the cause on my doorstep.
Mankind has far too high an opinion of itself, so it makes the leap that WE are causing this "problem", if it is one. I think it's just a natural phenomenon. Global warming proponents make me think of the time when we thought all the planets and the sun orbited the earth.
50 or even 100 years worth of data do not establish a trend, when we are talking about thousands of years.